Field
Exemplary embodiments relate to display technology, and more particularly to driving devices for display devices.
Discussion
In general, a display device includes a plurality of pixels (i.e., units for displaying images) and a plurality of drivers configured to drive the plurality of pixels.
Individual ones of the plurality of pixels are connected with corresponding ones of a plurality of gate lines and data lines. Each pixel may include a switching element, such as a thin film transistor, connected to corresponding ones of the plurality of gate lines and data lines. At least one pixel electrode is typically connected thereto. The plurality of gate lines and data lines may extend in different directions, and may cross each other, such as in a perpendicular (or substantially perpendicular) manner.
The plurality of drivers usually include a data driver configured to apply one or more data voltages to the plurality of data lines, a gate driver configured to apply one or more gate signals to the plurality of gate lines, and a signal controller configured to apply one or more control signals to the gate driver and the data driver to, thereby, control the gate driver and the data driver. In this manner, the signal controller is configured to control driving timings of the gate driver and the data driver, as well as configured to supply an image signal to the data driver.
The gate driver may include a shift register that, in turn, includes a plurality of stages that are subordinately connected to each other or at least one gate driving circuit. The gate driver is configured to receive a plurality of driving voltages and a plurality of gate control signals to generate gate signals. The plurality of driving voltages may include a gate on voltage configured to turn on corresponding switching elements and a gate off voltage configured to turn off the corresponding switching elements. The plurality of gate control signals may include a scanning start signal STV configured to instruct a scanning start, a gate clock signal CPV configured to control an output timing of a gate on pulse, and the like. The gate driver is configured to output gate on pulses to the plurality of gate lines in sequence.
The data driver is configured to apply the plurality of data voltages to the plurality of data lines whenever a gate on pulse is applied to a gate line so that a corresponding data voltage may be applied to a respective pixel via a corresponding switching element.
When the gate off voltage is applied to the thin film transistor, which is the switching element of each pixel, to turn off the thin film transistor, a voltage applied to each pixel may be changed according to one or more corresponding voltage changes associated with a parasitic capacitor of the thin film transistor and the gate signal. The voltage change is referred to as a kickback voltage. A flicker and/or other image distortions may be caused by deviations in the kickback voltage and, as such, image quality may be deteriorated. As a size of the display device becomes larger, a data charging time of the thin film transistor may be insufficient due to a delay of the gate on pulse caused by a load of the gate line. This too may cause image distortions or degradations.
Conventionally, the above-noted problems have been addressed by modifying the gate on voltage to generate the plurality of gate signals.
As display panels of display devices become larger, signal wires (or lines) configured to transfer the plurality of driving voltages and the plurality of gate control signals input to the gate driver are becoming longer and, as such, distortion in waveforms of the plurality of driving voltages and the plurality of gate control signals may result due to the load on the plurality of signal wires. As a result, a deviation in a level and a waveform of a gate on pulse may occur according to a position of the gate driving circuit, and a boundary between display areas corresponding to two gate driving circuits may be perceived by an observer. As such, image quality of the display device may become deteriorated.
Therefore, there is a need for an approach that provides efficient, cost effective techniques to drive display devices that can reduce (or otherwise prevent) deviations in the waveforms of gate-on pulses and, thereby, reduce (or otherwise prevent) image quality distortions or degradations.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and, therefore, it may contain information that does not form any part of the prior art nor what the prior art may suggest to a person of ordinary skill in the art.